Chalice blanks half of their spells. Calling it a card that don't do a whole lot against Miracles is misinformed.
Top, Swords and Pyroblast are very relevant against us, with Top being the most important card in their deck.
Brainstorm puts Terminus and Entreat on top. Stopping Ponder is nor here nor there.
Echoing Truth is counter against Entreat, huge tempo swing if they are on Batterskull plan or saves TNNs (or whatever I am "overextending" with) against Terminus. You can even Target their Top in response to its second ability, which delays any Miracle spell for a turn. If I bounce Top when I have Chalice on one they are not winning anymore. This is only a small number of examples what Truth can do.
Image can become Mutavault if I fear Terminus. Or their Clique.
Jitte isn't there to fight them. I have built a deck that can have good matchup against big decks like Miracles, Elves and Delver Decks, while covering graveyard and combo decks from the sideboard.
I looked at the last bigger legacy event (just copy the whole link) :
http://sales.starcitygames.com//deck...deckshow.php?t[T2]=3&event_ID=45&feedin=&start_date=05%2F15%2F2015&end_date=05%2F17%2F2015&city=&state=TX&country=&start=&finish=&exp=&p_first=&p_last=&simple_card_name[1]=&simple_card_name[2]=&simple_card_name[3]=&simple_card_name[4]=&simple_card_name[5]=&w_perc=0&g_perc=0&r_perc=0&b_perc=0&u_perc=0&a_perc=0&comparison[1]=%3E%3D&card_qty[1]=1&card_name[1]=&comparison[2]=%3E%3D&card_qty[2]=1&card_name[2]
Chalice covers majority of them. Try playing Standstill against Storm or Delver.
You are drawing Vial about 40ish % in opening hand and the same percentage is for Standstill if you have playsets of both in your deck. The times when you have both are not overlaping that often.
Standstill Merfolk deck with 20 creatures is a deck that tries to win the match very late in the game (two creatures on average in opening hand and Mutavault attacks under Standstill will not crush anyone with speed).
I am not convinced that you have the best late game deck in legacy. This all happens with Dazes and Spell Pierces in hand which lose value since both players are doing land, go.
Other decks are doing more powerful things than us and that is the reason I don't see Standstill version doing better than Chalice one.